While there are some not very widely supported theories out there that postulate some somehow Jewish origin for Columbus (esWP: Cristóbal Colón, Origen, Hipótesis secundarias, enWP: Catalan-Jewish hypothesis) this even if 'true' is not saying much about his beliefs and writing practices.
The claim to investigate here says very explicitly:
At the top ...
Did Portuguese fisherman frequent New England prior to 1492?
There is some evidence that first Basque, then Portuguese and finally English(Bristol) fishermen visited Newfoundland and/or Greenland before Columbus. As these fishermen were shut out of the lucrative Icelandic fisheries controlled by the Hanseatic League ( a merchant ...